Yeast-raised doughnuts and other yeast-raised or yeast-leavened baked goods, such as Danish pastries and croissants, are prized for their soft texture and their fresh yeasty flavor characteristics. Doughnuts are particularly recognized for their airy texture and distinctive fresh yeasty aroma and flavor. The primary components for commercial yeast raised doughnuts are flours, sugars, proteins, flavors, enzymes, emulsifiers, hydrocolloids, chemical leavenings, and fats and oils.
The current shelf life for the optimum quality of commercial yeast-raised doughnuts is about eight to ten hours. These doughnuts lose their eating quality xe2x80x9cfreshnessxe2x80x9d as they age and become stale. Staling is any change, other than microbiological spoiling, that occurs in doughnuts during storage and that makes them less acceptable to consumers. Staling occurs when the starch molecules crystallize or xe2x80x9cretrograde.xe2x80x9d Starch retrogradation occurs when the molecules of gelatinized starch reassociate in an ordered structure. In the initial phase, two or more starch molecular chains!form a simple juncture point that then may develop into more extensively ordered regions. Ultimately, this crystalline ordering causes the doughnuts to become stale.
The changes due to staling are sensory (flavor) and/or physical (loss of crumb softness). Regarding the flavor changes, stale doughnuts have an oxidized off flavor and/or lose the fresh yeasty flavor that is characteristic of fresh, yeast-raised doughnuts. Many consumers who are served xe2x80x9cstalexe2x80x9d doughnuts are dissatisfied. Thus, any improvement that could extend the shelf life of doughnuts or other baked goods and/or retard or delay staling would be beneficial.
The present invention relates to a commercial proofing oven or proofer for proofing the raw dough of yeast-raised baked goods that is able to extend the shelf life of yeast-raised baked goods, and particularly doughnuts, to twenty-four hours.
In particular, the proofer of the present invention includes an insulated housing and a proofing chamber within the housing to receive a rack for holding a raw dough product to be proofed. A dehumidifier, a heating unit, a humidifier, and an air circulator are provided within the housing, under control of a controller, to provide an airflow conditioned for proofing the raw dough product. These components are selected to return to their desired set points after preheating generally within ten to fifteen minutes after opening the door to ambient. The proofer includes at least one sensor comprising a relative humidity sensor or a temperature sensor located within the proofing chamber close to the raw dough product to provide an accurate reading of conditions at the product. Preferably, the proofer includes at least two relative humidity sensors, one mounted on a rear inside surface of the proofing chamber and one mounted on the inside surface of the door. Preferably, the proofer also includes a temperature sensor mounted on the inside surface of the door.
In a further aspect of the invention, the proofer includes a rear partition in the proofing chamber that includes two side panels each having a plurality of openings and vertical louvers disposed to provide a more uniform airflow in the proofing chamber. A rack positioning device is located within the proofing chamber to contact the rack and fix the rack in a desired position within the proofing chamber upon closure of the sealable door. A baker""s rack for holding raw dough to be proofed within a proofing chamber has an increased spacing between tiers to provide a less restricted airflow. Top and bottom covers may be used to cover the baker""s rack, to further control the airflow.
In this manner, the proofer of the present invention is able to maintain the temperature and relative humidity consistently within the desired ranges in the proofing chamber. The proofer is also able to return to the desired temperature and relative humidity quickly, generally within ten to fifteen minutes after opening the door. The air flow patterns in the proofing chamber give a spatially uniform temperature and relative humidity, resulting in more consistent product quality from position to position in the proofing chamber.
The present invention relates to a process for making dough of yeast-raised baked goods that extends the shelf life of yeast-raised baked goods, and particularly doughnuts, to twenty-four hours. The process comprises providing a yeast-raised dough at 85xc2x0 F. After mixing the dough, the dough is set to rest in the mixing bowl for 45 minutes. After resting, the dough is sheeted, shrunk, and formed into desired shapes. The dough is then proofed for a time appropriate for the type of desired baked good and dough cut. After proofing, the dough is baked to produce the final baked good. In the case of doughnuts, the doughnuts are fried in a suitable oil.
The present invention also provides a formulation for baking a yeast-raised baked good having an extended shelf life. The ingredients that contribute to the shelf life extension of the product are the hard wheat flour, soft wheat flour, dextrose, soybean oil, nonfat dry milk or milk replacement, the fermented flavor, gums, vital wheat gluten, distilled monoglycerides, enzymes, konjac flour, and methylcellulose.